If one drinks alcohol how long after that can one return to Al Masjid?

All perfect praise be to Allah, The Lord of the Worlds. I testify that there is none worthy of worship except Allah, and that Muhammad is His slave and Messenger.

It is forbidden to drink alcohol under any circumstances. There is evidence for this from the Quran, the Sunnah and the Muslim scholars' consensus. The reason for this prohibition is the fact that it causes the person to lose his mind. This, in turn, leads him to behave in a wrong way. The drunken person might, for instance, divorce his wife unwillingly, or might commit Zina (fornication or adultery), or even say something that takes him out of the fold of Islam; all this without being aware of what he says or does. This is why the Prophet called alcohol: “The mother of all evils”, as reported by An-Nasaa’i.

Moreover, ‘Uthmaan ibn ‘Affaan said: “Avoid Khamr for, by Allah, it can never coexist with Faith, but soon one of them will expel the other.” [An-Nasaa’i]

So, our advice to anyone who was afflicted by this vice to give it up immediately as this is compulsory on him. He should also have remorse for what he drank in the past and have firm resolution never to return to drinking it again. Moreover, one should befriend only pious people who would encourage him to do what is good and avoid what is evil, because evil people push one to indulge in evil acts that become a barrier between him and doing good.

As for when one can enter the mosque after having drunk alcohol, we say that he must first be able to discern what he says otherwise he should not enter the mosque. Allah Says (what means): {O you who have believed, do not approach prayer while you are intoxicated until you know what you are saying.} [Quran 4:43]

For more benefit on the prohibition of alcohol in Islam, please refer to Fataawa 81900, 81389, and 81461.

For more benefit on the conditions of sincere repentance, please refer to Fatwa 86527.

Allah knows best.